virtualbox.org

I have VirtualBox 6.1.34r (for Windows) installed.

Ubuntu 22.04 installation gets stuck
Debian 11.3 installation gets stuck
Ubuntu 20.04.4 installation gets stuck

The installation of Ubuntu 20.04.4 reported: CPU#3 stuck

If not caused by Windows update, then what is the latest stable version of VirtualBox?

6.1.34 works for most. But there could be settings on the host OS that may interfere.

Pick one VM. Start the VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.